Pile driving and extraction device

ABSTRACT

A device for driving and extraction of sheet piles into or from the ground, respectively, has a leader on which an exciter cell is guided. The exciter cell is coupled with an advancing system by way of which it can be moved in linear manner. The exciter cell is rigidly connected with at least one guide element that is exclusively guided on the leader and elastically connected with the advancing system.

CROSS REFERENCE TO RELATED APPLICATIONS

Applicants claim priority under 35 U.S.C. §119 of European ApplicationNo. 10013794,2 filed on Oct. 20, 2010, the disclosure of which isincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a device for driving and/or extraction of sheetpiles and the like into and from the ground, respectively. The devicecomprises a leader on which an exciter cell is guided. The exciter cellis coupled with an advancing system for moving it in a linear manner.

2. The Prior Art

Vibration generators, so-called exciter cells, are used for drivingsheet piles or the like into the ground and extracting them,respectively. These generators are attached to the lifting carriage of aleader of a construction machine, and a collet is provided on them, onwhich the sheet pile can be attached. Such an arrangement is known, forexample, from German Patent Application No. DE 43 12 368 A1. In thisconnection, the exciter cell is usually disposed in a hood, which isconnected with an equipment carriage that is connected with the liftingcarriage of the leader. The lifting carriage of the leader is coupledwith an advancing system by way of traction cables as well as loadcables. The load cables are disposed on the side of the lifting carriagethat faces the ground, so that a traction force that acts on the loadcable acts in the direction of the ground, in other words as a top load.Such arrangements have fundamentally proven themselves for introducingsheet piles into the ground or extracting them, respectively. However,there are significant friction losses as well as preload force losses atthe guide of the exciter cell in the hood and the guide of the liftingcarriage on the leader, caused by tilting and jamming of the guides.Furthermore, great wear is caused by this.

SUMMARY OF THE INVENTION

The present invention provides a device for driving and/or extraction ofsheet piles and the like into and from the ground, respectively,comprising a leader, on which an exciter cell is guided, in which devicesuch friction and preload force losses are reduced. The exciter cell isrigidly connected with at least one guide element that is exclusivelyguided on the leader and elastically connected with the advancingsystem.

By means of the rigid connection between the exciter cell and the atleast one guide element, which is exclusively guided on the leader,preload losses due to vibration and friction are eliminated to a greatextent. The vibrations that are now directly transferred to the leaderare uncoupled by way of the elastic connection between advancing systemand the at least one guide. In this connection, in the present case, theterm “elastic” connection is to be understood to mean a connection thathas clearly greater elasticity than the direct coupling by way of steelcables that is known in the state of the art, since these cablestransfer the vibrations transferred to the leader and would cause damageto the leader and/or to the advancing system in this connection.

In a further development of the invention, coupling of the at least oneguide element to the advancing system takes place by way of at least onecable that is configured to be elastic. Uncoupling of the vibrationsapplied to the leader by way of the at least one guide element isbrought about as the result of the elasticity of the cable. It isadvantageous if the at least one cable is produced from high-strengthplastic fibers, preferably polyethylene fibers made fromultra-high-crystalline molecular polyethylene or from glass fibers. Suchcables are characterized in that they demonstrate great elasticity and,simultaneously, low weight.

In the following, all elongated, flexible elements similar to cables,for the transfer of traction forces, including chains, for example, areto be subsumed in the term “cable.” In this connection, a cable whosetraction force acts in the direction of the ground is referred to as a“load cable,” and a cable whose traction force acts counter to theground is referred to as a “traction cable.”

In another embodiment of the invention, coupling of the at least oneguide element to the advancing system takes place by way of at least onecable, whereby at least one cable is connected with at least one springmodule. In this way, uncoupling of the vibrations applied to the leaderby way of the at least one guide element is achieved. In thisconnection, the at least one spring module can be configured as a springpacket composed of cylindrical helical springs, plate springs, gaspressure springs, torsion bar springs and/or flexion springs.

In another embodiment of the invention, the at least one spring moduleis formed from at least one rocker, which is connected with the at leastone guide element by way of an axle, so as to pivot. A first clampingunit is disposed on the at least one rocker, at a distance from itspivot axle, and a second clamping unit for an elastic element,preferably an elastic loop, is disposed at a distance from the rocker.At least one cable is attached to the rocker on the side that liesopposite the pivot axle. In this connection, the elastic element,preferably the elastic loop, takes on uncoupling of the vibrationsapplied to the leader by way of the at least one guide element.Additional securing is brought about in that even in the event offailure of the elastic element or the elastic loop, the at least oneguide element continues to be connected with the at least one tractioncable by way of the at least one rocker.

In a further development of the invention, two such rockers are disposedon the at least one guide element, vertically spaced apart from oneanother and preferably projecting in opposite directions. One rocker isconnected with at least one traction cable and one rocker is connectedwith at least one load cable. The elastic element assigned to eachrocker, which is preferably configured as an elastic loop, is disposedon the pivot axle of the opposite rocker, connected with the at leastone guide element. In this way, uncoupling of the vibrations applied tothe leader is achieved by two elastic elements or elastic loops. Oneelastic element brings about uncoupling when stress is applied by thetraction cable, and one elastic cable brings about uncoupling whenstress is applied by the load cable. In this way, the stress on theelastic elements is reduced, thereby increasing their useful lifetime.Furthermore, the preload force for traction and pressure can be adjustedseparately, by the use of different loops. With this arrangement, alinear spring characteristic line is achieved, which allows gooduncoupling. It is advantageous if the pivot axle of the first rocker isdisposed horizontally offset from the pivot axle of the second rocker.

It is advantageous if the elastic elements are configured as elasticloops that are produced from glass-fiber-reinforced plastic material.This material has good elastic properties. In this connection, thefibers are durable for a very long time and have great resistance tofriction wear, moisture, and UV radiation.

In an embodiment of the invention, the at least one guide element isdisposed on a carriage that is rigidly connected with the exciter cell.In this connection, the carriage preferably has a length that projectsbeyond the exciter cell in terms of its length. The force that acts onthe at least one guide element is reduced by the use of a long carriage.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and features of the present invention will become apparentfrom the following detailed description considered in connection withthe accompanying drawings. It is to be understood, however, that thedrawings are designed as an illustration only and not as a definition ofthe limits of the invention.

In the drawings, wherein similar reference characters denote similarelements throughout the several views:

FIG. 1 shows the spatial representation of the exciter cell withcarriage disposed on it, and coupling to an advancing system;

FIG. 2 shows the schematic representation of the exciter cell withcarriage disposed on it, with an alternative spring module;

FIG. 3 shows the schematic representation of an exciter cell withcarriage disposed on it, with a spring module in a third embodiment, and

FIG. 4 shows the arrangement from FIG. 3 under the effect of a tractionforce on the traction cable.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now in detail to the drawings, the device for driving and/orextraction of sheet piles into or from the ground, respectively,selected as an exemplary embodiment, essentially consists of leader 7disposed on a construction machine, having a carriage 2 that is disposedto be displaceable on a leader guide 71. An exciter cell 1 is attachedto the carriage 2, on which cell a collet 11 for accommodating a sheetpile is disposed on the bottom side. Carriage 2 is connected with theadvancing system of leader 7 by way of traction cables 3 attached oncarriage 2 on both sides, as well as by way of load cables 4 disposed oncarriage 2 on both sides. The guide of cables 3, 4 as well as theirconnection with the advancing system, are known, for example, from DE 4312 368 A1, and therefore do not need to be described further at thispoint. The same holds true for the structure of exciter cell 1. Suchvibration generators are known to a person skilled in the art, in themost varied embodiments.

In the exemplary embodiment, exciter cell 1 has an extensivelyblock-shaped housing that is disposed between two side cheeks 20 ofcarriage 2, which are disposed parallel, and is connected with theseside cheeks 20 by way of screw connections. On its side facing away fromexciter cell 1, two guide rails 21 are disposed on carriage 2, at adistance from one another, by way of which carriage 2 is mounted onleader 7 in a displaceable manner. Laterally, projecting metal sheets 22are affixed to guide rails 21. In this connection, metal sheets 22 aredisposed in such a manner that metal sheets 22 of upper guide rail 21project in the direction of leader 7, and metal sheets 22 of lower guiderail 21, which faces the ground, project in the direction of the excitercell 1. An axle 221 for attachment of a traction cable 3 or a load cable4, respectively, is disposed on each of metal sheets 22. In thisconnection, traction cables 3 engage on axles 221 of metal sheets 22 oflower guide rail 21; load cables 4 are connected with axles 221 of metalsheets 22 of upper guide rail 21. Spring packets 5 are integrated intotraction cables 3 and load cables 4, which packets are represented, insimplified form, as cylindrical helical springs in FIG. 1. Tractioncables 3 and load cables 4 are connected with axles 221 of metal sheets22 by way of eyes 31, 41.

Furthermore, a hydraulic block 6 for connecting hydraulic lines—notshown—is disposed on carriage 2, opposite the upper guide rail 21. Inthis connection, hydraulic block 6 is connected with carriage 2 by wayof resilient elements, so that transfer of vibrations to the connectedhydraulic lines is minimized. In the exemplary embodiment, the resilientelements are formed by elastomer blocks 61.

In the embodiment according to FIG. 2, a rocker 23 is connected withguide rail 21, so as to pivot, by way of a pivot axle 231, on both sidesof upper guide rail 21. In this connection, the force engagement pointsof cables 3, 4 as well as the traction/load loop 233 are disposed offsetfrom pivot axle 231 of rocker 23. Traction cable 3 and load cable 4 areattached to rocker 23 on a common vertical axis. A clamping axle 232 foraccommodating a traction/load loop 233 is disposed on the rocker 23, ata distance from pivot axle 231. The traction/load loop 233 is clampedbetween clamping axle 232 and a second clamping axle 24 disposed onlower guide rail 21.

The spring module of the arrangement according to FIG. 2 functions asfollows: If a traction force is applied to traction cable 3, then rocker23 pivots about axle 231, thereby causing clamping axle 232 to describean arc in the clockwise direction. This causes traction/load loop 233 tobe tensed, thereby achieving the desired uncoupling. To apply a top loadto exciter cell 1, a traction force is applied to load cable 4, therebypivoting rocker 23 in the counter-clockwise direction, about pivot axle231. In this connection, clamping axle 232 describes an arc in thecounter-clockwise direction, thereby again tensing traction/load loop233, which brings about uncoupling.

In the embodiment according to FIG. 3, a rocker 25, 26 is disposed bothon upper guide rail 21 and on lower guide rail 21, on both sides. Inthis connection, a traction rocker 25 is mounted on guide rail 21,eccentrically on upper guide rail 21, on both sides, by way of a pivotaxle 251, in such a manner that it projects in the direction of excitercell 1. Similarly, a load rocker 26 is connected with guide rail 21, soas to pivot, by way of an eccentrically disposed pivot axle 261, onlower guide rail 21 of the carriage 2, on both sides. Load rocker 26 isdisposed to project in the direction of leader 7. Clamping axles 252,262 are disposed on rockers 25, 26, offset from pivot axle 251, 261. Inthis connection, clamping axles 252, 262 are positioned in such a mannerthat they are positioned to lie opposite each of the pivot axles 251,261 of the opposite rockers 25, 26, in the case of horizontalorientation of the rockers 25, 26. A load loop 263 extends betweenclamping axle 262 of the load rocker 26 and pivot axle 251 of tractionrocker 25, and an elastic traction loop 253 extends between pivot axle261 of load rocker 26 and clamping axle 252 of traction rocker 25, onboth sides of guide rails 21. Traction loop 253 and load loop 263 areproduced from glass-fiber-reinforced plastic material. Alternatively,these loops can also be produced from high-strength plastic fibers, forexample from ultra-high-crystalline molecular polyethylene.

The method of functioning of the arrangement according to FIG. 3 isillustrated in FIG. 4. If a traction force F is applied to tractioncable 3, traction rocker 25 is displaced by preload path s, therebyincreasing the distance between pivot axle 261 of load rocker 26 andclamping axle 252 of the traction rocker. In this way, traction loop 253is tensed, thereby achieving uncoupling. The distance between pivot axle251 of traction rocker 25 and clamping axle 262 of load rocker 26remains unchanged. When a traction force is applied to load cable 4,load loop 263 is tensed accordingly. Traction loop 253 remainsunstressed. In the case of an alternating driving and extractionprocess, alternate stress on traction loop 253 and load loop 263therefore takes place, thereby achieving uncoupling. In this connection,the preload force for “driving” and “extraction” can be separatelyadjusted by separate dimensioning of traction loop 253 and load loop263. In the case of this embodiment, as well, carriage 2 continues to beconnected with traction cable 3, by way of traction rocker 25, in theevent of failure of traction loop 253 and/or load loop 263.

Accordingly, while only a few embodiments of the present invention havebeen shown and described, it is obvious that many changes andmodifications may be made thereunto without departing from the spiritand scope of the invention.

1. A device for driving and/or extraction of sheet piles into and fromthe ground, respectively, comprising: a leader on which an exciter cellis guided; an advancing system coupled to the exciter cell, theadvancing system being adapted to move the exciter cell in a linearmanner; and at least one guide element rigidly connected with theexciter cell, wherein the at least one guide element is exclusivelyguided on the leader and elastically connected with the advancingsystem.
 2. The device according to claim 1, wherein the at least oneguide element is coupled to the advancing system by at least one elasticcable.
 3. The device according to claim 2, wherein the at least oneelastic cable is produced from polyethylene fibers composed ofultra-high-crystalline molecular polyethylene, or from glass fibers. 4.The device according to claim 1, wherein the at least one guide elementis coupled to the advancing system by at least one cable connected withat least one spring module.
 5. The device according to claim 4, whereinthe at least one spring module is configured as a spring packet composedof springs selected from the group consisting of cylindrical helicalsprings, plate springs, gas pressure springs, torsion bar springs andflexion springs.
 6. The device according to claim 4, wherein the atleast one spring module is formed from at least one rocker, which isconnected with the at least one guide element by way of an axle, so asto pivot, wherein a first clamping unit is disposed on the at least onerocker, at a distance from its axle, and a second clamping unit for anelastic element is disposed at a distance from the rocker, and whereinat least one cable is attached to the rocker on a side that liesopposite the axle.
 7. The device according to claim 6, wherein tworockers are disposed on the at least one guide element, verticallyspaced apart from one another, wherein one of said rockers is connectedwith at least one traction cable and the other of said rockers isconnected with at least one load cable, and wherein the elastic elementassigned to each rocker is disposed on the pivot axle of the oppositerocker, connected with the at least one guide element.
 8. The deviceaccording to claim 7, wherein the pivot axle of the first rocker isdisposed horizontally offset from the pivot axle of the second rocker.9. The device according to claim 6, wherein the elastic element is inthe form of an elastic loop.
 10. The device according to claim 9,wherein the elastic loop is produced from glass-fiber-reinforcedplastic.
 11. The device according to claim 1, wherein the at least oneguide element is disposed on a carriage that is rigidly connected withthe exciter cell.
 12. The device according to claim 11, wherein thecarriage has a length that projects beyond a length of the exciter cell.